What are the side effects of buspirone (anxiolytic medication)?

Buspirone Side Effects

The most common side effects of buspirone include dizziness, nausea, headache, nervousness, lightheadedness, and excitement, which occur more frequently than with placebo. 1

Common Side Effects

Buspirone's side effect profile is categorized by body system:

Central Nervous System Effects

• Dizziness (12% vs 3% with placebo) 1
• Drowsiness (10% vs 9% with placebo) 1
• Nervousness (5% vs 1% with placebo) 1
• Insomnia (3% vs 3% with placebo) 1
• Lightheadedness (3% vs <1% with placebo) 1
• Dream disturbances (reported as frequent) 1
• Headache (6% vs 3% with placebo) 1

Gastrointestinal Effects

• Nausea (8% vs 5% with placebo) 1
• Dry mouth (3% vs 4% with placebo) 1
• Abdominal/gastric distress (2% vs 2% with placebo) 1

Other Common Effects

• Fatigue (4% vs 4% with placebo) 1
• Tinnitus, sore throat, and nasal congestion (reported as frequent) 1

Less Common Side Effects

Cardiovascular

• Nonspecific chest pain (frequent) 1
• Tachycardia/palpitations (1% vs 1% with placebo) 1
• Syncope, hypotension, and hypertension (infrequent) 1

Sexual Function

• Decreased or increased libido (infrequent) 1
• Delayed ejaculation and impotence (rare) 1

Skin

• Skin rash (1% vs <1% with placebo) 1
• Sweating/clamminess (1% vs <1% with placebo) 1

Rare but Serious Side Effects

• Seizures (rare) 1
• Suicidal ideation (infrequent) 1
• Hallucinations (infrequent) 1
• Involuntary movements (infrequent) 1
• Allergic reactions including urticaria and angioedema (rare in postmarketing reports) 1
• Extrapyramidal symptoms and dyskinesias (rare in postmarketing reports) 1

Pharmacokinetic Considerations

• Buspirone has a short half-life of approximately 2.5 hours 2
• It has low bioavailability (approximately 4%) 2
• Food increases peak concentration and area under the curve by 2-fold 2
• Patients with hepatic impairment may experience 15-fold higher drug concentrations 2

Special Considerations

Advantages Over Other Anxiolytics

• Unlike benzodiazepines, buspirone lacks anticonvulsant and muscle-relaxant properties 3
• Causes minimal sedation compared to benzodiazepines 3
• No evidence of abuse potential, dependence, or withdrawal symptoms 3
• Does not potentiate the effects of alcohol 3

Cautions

• Buspirone may take 2-4 weeks to become effective for anxiety management 4
• Useful only in patients with mild to moderate agitation 4
• May worsen psychotic symptoms in patients with schizoaffective disorder or other psychotic disorders 5
• Drug interactions with verapamil, diltiazem, erythromycin, and itraconazole can substantially increase buspirone plasma concentrations 2
• Rifampicin can decrease buspirone plasma concentrations by nearly 10-fold 2

Dosing

• Initial dosage typically starts at 5 mg twice daily 4
• Maximum recommended dosage is 20 mg three times daily 4
• Dosage should be adjusted for patients with hepatic or renal impairment 2

Buspirone represents a unique anxiolytic option with a different side effect profile than benzodiazepines, making it particularly useful for patients who cannot tolerate benzodiazepine-related side effects or who have a history of substance abuse 3, 6.